The human remains were found at a house on East 83rd Street in Canarsie around 1:30 p.m. on Tuesday.

A plumber doing work on the main sewer line in the basement made the grisly discovery, cops said.

The 38-year-old resident, who was three months pregnant, told police that she was aware of her pregnancy — but did not go to the doctor because she is an undocumented immigrant and had no way to pay for her care, according to the sources.

She told cops that she had been having plumbing problems since the incident took place and informed the landlord, who called the plumber, the sources said.

The incident is being ruled a miscarriage pending the autopsy report by the city Medical Examiner’s office, according to the sources.